In one aspect, the invention relates to a carbon black reactor. In another aspect, the invention relates to a process for producing carbon black. In yet another aspect, the invention relates to at least partially converting a swirl flow carbon black reactor into a more axial flow reactor.
Turbulence in the carbon black reactor has a large influence on the properties of the carbon black particles produced. It must be recognized, however, that turbulence other than in the region of active carbon formation has little influence on the process and simply causes high pressure drop.
At least four factors assist in the creation of turbulence in the carbon forming zone. These factors are combustion gas turbulence, combustion generated turbulence, expansion turbulence, and wall friction turbulence.
Combustion gas turbulence can be affected by whether the combustion gases have a swirling motion when they enter the zone of carbon formation. Combustion generated turbulence is generally brought about by providing the combustion gases with some free oxygen to burn a portion of the oil feedstock and assist in vaporization of the oil droplets. Expansion turbulence can be brought about by passing the reaction mass through a constriction followed by one or more expansions in the reaction passage positioned so as to determine at least a portion of the zone of carbon formation. Well friction turbulence can be influenced by the shape of the materials defining the outer limits of the reaction flow passage.
Because turbulence divides the carbon into particles and promotes interaction between the particles it has a large effect on resultant carbon black properties, especially surface area and structure. Provision for providing and controlling the amount of turbulence in the carbon forming zone of a reactor would clearly be very desirable.